scholarly journals Dual Regulatory Roles of the Extended N Terminus for Activation of the Tomato Mi-1.2 Resistance Protein

2012 ◽  
Vol 25 (8) ◽  
pp. 1045-1057 ◽  
Author(s):  
Ewa Lukasik-Shreepaathy ◽  
Erik Slootweg ◽  
Hanna Richter ◽  
Aska Goverse ◽  
Ben J. C. Cornelissen ◽  
...  
Keyword(s):  
Cell Death ◽  
Coiled Coil ◽  
Terminal Region ◽  
Regulatory Function ◽  
Cell Death Response ◽  
N Terminus ◽  
Positive Regulators ◽  
In Trans ◽  
Lrr Protein

Plant resistance (R) proteins mediate race-specific immunity and initiate host defenses that are often accompanied by a localized cell-death response. Most R proteins belong to the nucleotide binding-leucine-rich repeat (NB-LRR) protein family, as they carry a central NB-ARC domain fused to an LRR domain. The coiled-coil (CC) domain at the N terminus of some solanaceous NB-LRR proteins is extended with a solanaceae domain (SD). Tomato Mi-1.2, which confers resistance against nematodes, white flies, psyllids, and aphids, encodes a typical SD-CNL protein. Here, we analyzed the role of the extended N terminus for Mi-1.2 activation. Removal of the first part of the N terminus (Nt1) induced Mi-1.2-mediated cell death that could be suppressed by overexpression of the second half of the N-terminal region. Yet, autoactivating NB-ARC-LRR mutants require in trans coexpression of the N-terminal region to induce cell death, indicating that the N terminus functions both as a negative and as a positive regulator. Based on secondary structure predictions, we could link both activities to three distinct subdomains, a typical CC domain and two novel, structurally-conserved helical subdomains called SD1 and SD2. A negative regulatory function could be assigned to the SD1, whereas SD2 and the CC together function as positive regulators of Mi-1.2-mediated cell death.

scholarly journals Coiled-coil and RPW8-type immune receptors function at the plasma membrane in a phospholipid dependent manner

2020 ◽  
Author(s):  
Svenja C. Saile ◽  
Frank M. Ackermann ◽  
Sruthi Sunil ◽  
Adam Bayless ◽  
Eva Stöbbe ◽  
...  
Keyword(s):  
Cell Death ◽  
Plasma Membrane ◽  
Coiled Coil ◽  
Dependent Manner ◽  
Leucine Rich Repeat ◽  
Cell Death Response ◽  
Infected Cells ◽  
Self Association ◽  
Phosphatidylinositol 4

AbstractActivation of intracellular nucleotide-binding leucine-rich repeat receptors (NLRs) results in immunity and a localized cell death response of infected cells. Cell death activity of many NLRs requires oligomerization and in some cases plasma membrane (PM) localization. However, the exact mechanisms underlying PM localization of NLRs lacking recognizable N- or C-terminal lipidation motifs or predicted transmembrane domains remains elusive. Here we show that the PM localization and stability of members of the RPW8-like coiled-coil (CCR) domain NLRs (RNLs) and a CC-type NLR (CNL) depend on the interaction with PM phospholipids. Depletion of phosphatidylinositol-4-phosphate (PI4P) from the PM led to a mislocalization of the analyzed NLRs and consequently inhibited their cell death activity. We further demonstrate activation-dependent self-association of cell death inducing RNLs. Our results provide new insights into the molecular mechanism of NLR PM localization and defines an important role of phospholipids for CNL and RNL activity during immunity.

scholarly journals OsJAZ13 Negatively Regulates Jasmonate Signaling and Activates Hypersensitive Cell Death Response in Rice

2020 ◽  
Vol 21 (12) ◽  
pp. 4379
Author(s):  
Xiujing Feng ◽  
Lei Zhang ◽  
Xiaoli Wei ◽  
Yun Zhou ◽  
Yan Dai ◽  
...  
Keyword(s):  
Cell Death ◽  
Splice Variants ◽  
Adaptor Protein ◽  
Dependent Manner ◽  
Hypersensitive Cell Death ◽  
Cell Death Response ◽  
Jaz Proteins ◽  
Localization Analysis ◽  
And Function

Jasmonate ZIM-domain (JAZ) proteins belong to the subgroup of TIFY family and act as key regulators of jasmonate (JA) responses in plants. To date, only a few JAZ proteins have been characterized in rice. Here, we report the identification and function of rice OsJAZ13 gene. The gene encodes three different splice variants: OsJAZ13a, OsJAZ13b, and OsJAZ13c. The expression of OsJAZ13 was mainly activated in vegetative tissues and transiently responded to JA and ethylene. Subcellular localization analysis indicated OsJAZ13a is a nuclear protein. Yeast two-hybrid assays revealed OsJAZ13a directly interacts with OsMYC2, and also with OsCOI1, in a COR-dependent manner. Furthermore, OsJAZ13a recruited a general co-repressor OsTPL via an adaptor protein OsNINJA. Remarkably, overexpression of OsJAZ13a resulted in the attenuation of root by methyl JA. Furthermore, OsJAZ13a-overexpressing plants developed lesion mimics in the sheath after approximately 30–45 days of growth. Tillers with necrosis died a few days later. Gene-expression analysis suggested the role of OsJAZ13 in modulating the expression of JA/ethylene response-related genes to regulate growth and activate hypersensitive cell death. Taken together, these observations describe a novel regulatory mechanism in rice and provide the basis for elucidating the function of OsJAZ13 in signal transduction and cell death in plants.

scholarly journals Coassembly of Mgm1 isoforms requires cardiolipin and mediates mitochondrial inner membrane fusion

2009 ◽  
Vol 186 (6) ◽  
pp. 793-803 ◽  
Author(s):  
Rachel M. DeVay ◽  
Lenin Dominguez-Ramirez ◽  
Laura L. Lackner ◽  
Suzanne Hoppins ◽  
Henning Stahlberg ◽  
...  
Keyword(s):  
Membrane Fusion ◽  
Coiled Coil ◽  
Intermembrane Space ◽  
Dependent Manner ◽  
Related Protein ◽  
Mitochondrial Membranes ◽  
Inner Membrane ◽  
Mitochondrial Inner Membrane ◽  
N Terminus ◽  
In Trans

Two dynamin-related protein (DRP) families are essential for fusion of the outer and inner mitochondrial membranes, Fzo1 (yeast)/Mfn1/Mfn2 (mammals) and Mgm1 (yeast)/Opa1 (mammals), respectively. Fzo1/Mfns possess two medial transmembrane domains, which place their critical GTPase and coiled-coil domains in the cytosol. In contrast, Mgm1/Opa1 are present in cells as long (l) isoforms that are anchored via the N terminus to the inner membrane, and short (s) isoforms were predicted to be soluble in the intermembrane space. We addressed the roles of Mgm1 isoforms and how DRPs function in membrane fusion. Our analysis indicates that in the absence of a membrane, l- and s-Mgm1 both exist as inactive GTPase monomers, but that together in trans they form a functional dimer in a cardiolipin-dependent manner that is the building block for higher-order assemblies.

scholarly journals Role of the TFG N-terminus and coiled-coil domain in the transforming activity of the thyroid TRK-T3 oncogene

Oncogene ◽  
1998 ◽  
Vol 16 (6) ◽  
pp. 809-816 ◽  
Author(s):  
Angela Greco ◽  
Lisa Fusetti ◽  
Claudia Miranda ◽  
Riccardo Villa ◽  
Simona Zanotti ◽  
...  
Keyword(s):  
Coiled Coil ◽  
Coiled Coil Domain ◽  
N Terminus ◽  
Transforming Activity

scholarly journals The helper NLR immune protein NRC3 mediates the hypersensitive cell death caused by the cell-surface receptor Cf-4

2021 ◽  
Author(s):  
Jiorgos Kourelis ◽  
Mauricio P. Contreras ◽  
Adeline Harant ◽  
Hiroaki Adachi ◽  
Lida Derevnina ◽  
...  
Keyword(s):  
Cell Death ◽  
Cell Surface ◽  
Immune Responses ◽  
Coiled Coil ◽  
Chimeric Protein ◽  
Cell Surface Receptor ◽  
Surface Pattern ◽  
Hypersensitive Cell Death ◽  
Cell Death Response ◽  
Surface Receptor

Cell surface pattern recognition receptors (PRRs) activate immune responses that can include the hypersensitive cell death. However, the pathways that link PRRs to the cell death response are poorly understood. Here, we show that the cell surface receptor-like protein Cf-4 requires the intracellular nucleotide-binding domain leucine-rich repeat containing receptor (NLR) NRC3 to trigger a confluent cell death response upon detection of the fungal effector Avr4 in leaves of Nicotiana benthamiana. This NRC3 activity requires an intact N-terminal MADA motif, a conserved signature of coiled-coil (CC)-type plant NLRs that is required for resistosome-mediated immune responses. A chimeric protein with the N-terminal α1 helix of Arabidopsis ZAR1 swapped into NRC3 retains the capacity to mediate Cf-4 hypersensitive cell death. Pathogen effectors acting as suppressors of NRC3 can suppress Cf-4-triggered hypersensitive cell-death. Our findings link the NLR resistosome model to the hypersensitive cell death caused by a cell surface PRR.

scholarly journals Localization of BCR-ABL to stress granules contributes to its oncogenic function

2019 ◽  
Author(s):  
Sayaka Kashiwagi ◽  
Yoichiro Fujioka ◽  
Takeshi Kondo ◽  
Aya O. Satoh ◽  
Aiko Yoshida ◽  
...  
Keyword(s):  
Kinase Inhibitor ◽  
Coiled Coil ◽  
Chimeric Protein ◽  
Stress Granules ◽  
Terminal Region ◽  
Myelogenous Leukemia ◽  
Growth Defect ◽  
Causative Role ◽  
Granule Formation ◽  
N Terminus

ABSTRACTThe oncogenic tyrosine kinase BCR-ABL activates a variety of signaling pathways and plays a causative role in the pathogenesis of chronic myelogenous leukemia (CML); however, the subcellular distribution of this chimeric protein remains controversial. Here, we report that BCR-ABL is localized to stress granules and that its granular localization contributes to BCR-ABL-dependent leukemogenesis. BCR-ABL-positive granules were not colocalized with any markers for membrane-bound organelles but were colocalized with HSP90a, a component of RNA granules. The number of such granules increased with thapsigargin treatment, confirming that the granules were stress granules. Given that treatment with the ABL kinase inhibitor imatinib and elimination of the N-terminal region of BCR-ABL abolished granule formation, kinase activity and the coiled-coil domain are required for granule formation. Whereas wild-type BCR-ABL rescued the growth defect in IL-3-depleted Ba/F3 cells, mutant BCR-ABL lacking the N-terminal region failed to do so. Moreover, forced tetramerization of the N-terminus-deleted mutant could not restore the growth defect, indicating that granule formation, but not tetramerization, through its N-terminus is critical for BCR-ABL-dependent oncogenicity. Our findings together provide new insights into the pathogenesis of CML by BCR-ABL and open a window for developing novel therapeutic strategies for this disease.

Expression in Escherichia coli of fragments of the coiled-coil rod domain of rabbit myosin: influence of different regions of the molecule on aggregation and paracrystal formation

1991 ◽  
Vol 99 (4) ◽  
pp. 823-836
Author(s):  
S.J. Atkinson ◽  
M. Stewart
Keyword(s):  
Escherichia Coli ◽  
Ionic Strength ◽  
Coiled Coil ◽  
Periodic Variation ◽  
Heptad Repeat ◽  
C Terminus ◽  
N Terminus ◽  
Low Ionic Strength ◽  
Myosin Rod

We have expressed in Escherichia coli a cDNA clone corresponding broadly to rabbit light meromyosin (LMM) together with a number of modified polypeptides and have used this material to investigate the role of different aspects of molecular structure on the solubility properties of LMM. The expressed material was characterized biochemically and structurally to ensure that it retained the coiled-coil conformation of the native molecule. Full-length recombinant LMM retained the general solubility properties of myosin and, although soluble at high ionic strength, precipitated when the ionic strength was reduced below 0.3 M. Constructs in which the ‘skip’ residues (that disrupt the coiled-coil heptad repeat) were deleted had solubility properties indistinguishable from the wild type, which indicated that the skip residues did not play a major role in determining the molecular interactions involved in assembly. Deletions from the N terminus of LMM did not alter the solubility properties of the expressed material, but deletion of 92 residues from the C terminus caused a large increase in solubility at low ionic strength, indicating that a determinant important for interaction between LMM molecules was located in this region. The failure of deletions from the molecule's N terminus to alter its solubility radically suggested that the periodic variation of charge along the myosin rod may not be as important as proposed for determining the strength of binding between molecules and thus the solubility of myosin.

scholarly journals Evidence for a Role of the N Terminus and Leucine-Rich Repeat Region of the Mi Gene Product in Regulation of Localized Cell Death

2000 ◽  
Vol 12 (8) ◽  
pp. 1319-1329 ◽  
Author(s):  
Chin-Feng Hwang ◽  
Amit V. Bhakta ◽  
Gina M. Truesdell ◽  
Waclawa M. Pudlo ◽  
Valerie Moroz Williamson
Keyword(s):  
Cell Death ◽  
Gene Product ◽  
Leucine Rich Repeat ◽  
Repeat Region ◽  
N Terminus ◽  
Mi Gene

scholarly journals The GHKL ATPase MORC1 Modulates Species-Specific Plant Immunity in Solanaceae

2015 ◽  
Vol 28 (8) ◽  
pp. 927-942 ◽  
Author(s):  
Patricia Manosalva ◽  
Murli Manohar ◽  
Karl-Heinz Kogel ◽  
Hong-Gu Kang ◽  
Daniel F. Klessig
Keyword(s):  
Cell Death ◽  
Transient Expression ◽  
Plant Immunity ◽  
Terminal Region ◽  
Transcriptional Gene Silencing ◽  
Basal Resistance ◽  
Specific Effects ◽  
Oomycete Pathogen ◽  
Species Specific

The microrchidia (MORC) proteins, a subset of the GHKL ATPase superfamily, were recently described as components involved in transcriptional gene silencing and plant immunity in Arabidopsis. To assess the role of MORC1 during resistance to Phytophthora infestans in solanaceous species, we altered the expression of the corresponding MORC1 homologs in potato, tomato, and Nicotiana benthamiana. Basal resistance to P. infestans was compromised in StMORC1-silenced potato and enhanced in overexpressing lines, indicating that StMORC1 positively affects immunity. By contrast, silencing SlMORC1 expression in tomato or NbMORC1 expression in N. benthamiana enhanced basal resistance to this oomycete pathogen. In addition, silencing SlMORC1 further enhanced resistance conferred by two resistance genes in tomato. Transient expression of StMORC1 in N. benthamiana accelerated cell death induced by infestin1 (INF1), whereas SlMORC1 or NbMORC1 suppressed it. Domain-swapping and mutational analyses indicated that the C-terminal region dictates the species-specific effects of the solanaceous MORC1 proteins on INF1-induced cell death. This C-terminal region also was required for homodimerization and phosphorylation of recombinant StMORC1 and SlMORC1, and its transient expression induced spontaneous cell death in N. benthamiana. Thus, this C-terminal region likely plays important roles in both determining and modulating the biological activity of MORC1 proteins.

Evidence for a Role of the N Terminus and Leucine-Rich Repeat Region of the Mi Gene Product in Regulation of Localized Cell Death

2000 ◽  
Vol 12 (8) ◽  
pp. 1319 ◽  
Author(s):  
Chin-Feng Hwang ◽  
Amit V. Bhakta ◽  
Gina M. Truesdell ◽  
Waclawa M. Pudlo ◽  
Valerie Moroz Williamson
Keyword(s):  
Cell Death ◽  
Gene Product ◽  
Leucine Rich Repeat ◽  
Repeat Region ◽  
N Terminus ◽  
Mi Gene
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